Call me selfish, but I don't care if eating grains will help to better adapt future generations to survive on them. I'm doing what makes me feel best so that I can live the best life possible; this includes eating plenty of pastured beef, seafood, and veggies with an occasional piece of fruit and sweet potato/yam. My body is loving me for it.
Also, to address your concern of only US citizens following the PB: There are numerous forum members from Canada, Sweden, Norway, Finland, the UK, Italy, New Zealand, Australia, and The Pacific Islands (Samoa) just to name a few. I'm sure there's representation from nearly any country with the privilege to access information via the internet.